Haematology: Fanconi anaemia: practice question

A Pathology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

Try it

Pathology · Haematology: Fanconi anaemia

Sample item

A 7-year-old boy has short stature, café-au-lait macules, absent thumbs and progressive pancytopenia. Which investigation is most likely to confirm the diagnosis?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Chromosomal breakage test with diepoxybutane or mitomycin C

Fanconi anaemia is an inherited DNA interstrand cross-link repair disorder that causes bone marrow failure, congenital anomalies such as radial ray defects and a high risk of acute myeloid leukaemia and squamous cancers. Cells show increased chromosomal breaks after exposure to cross-linking agents like diepoxybutane or mitomycin C. Haematopoietic stem cell transplantation is the curative treatment for marrow failure.

Option by option

  • A. Direct antiglobulin test

    A direct antiglobulin test detects autoimmune haemolysis, and it is not the cause of marrow failure with limb defects.

  • B. Flow cytometry for CD55 and CD59

    CD55 and CD59 flow cytometry diagnoses PNH, which does not cause congenital anomalies.

  • C. Osmotic fragility test

    Osmotic fragility testing diagnoses hereditary spherocytosis, which is not a cause of pancytopenia.

  • D. Chromosomal breakage test with diepoxybutane or mitomycin C (correct)

    Excess chromosome breakage with cross-linking agents is the diagnostic test.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Pathology questions

Questions about this Pathology question

What is the answer to this Pathology question?

The best answer is D, Chromosomal breakage test with diepoxybutane or mitomycin C. Fanconi anaemia is an inherited DNA interstrand cross-link repair disorder that causes bone marrow failure, congenital anomalies such as radial ray defects and a high risk of acute myeloid leukaemia and squamous cancers.

Why is "Direct antiglobulin test" not the answer?

A direct antiglobulin test detects autoimmune haemolysis, and it is not the cause of marrow failure with limb defects.

Why is "Flow cytometry for CD55 and CD59" not the answer?

CD55 and CD59 flow cytometry diagnoses PNH, which does not cause congenital anomalies.

Why is "Osmotic fragility test" not the answer?

Osmotic fragility testing diagnoses hereditary spherocytosis, which is not a cause of pancytopenia.

What concept does this question test?

It tests Haematology: Fanconi anaemia in Pathology. Cells show increased chromosomal breaks after exposure to cross-linking agents like diepoxybutane or mitomycin C. Haematopoietic stem cell transplantation is the curative treatment for marrow failure.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Haematology: Fanconi anaemia?

Learn each disease as a bundle: cause, key histology, markers, and the clinical hallmark. Then use the flashcards and the other Pathology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.